Analyzing UV/Vis/NIR Spectra-Addition of Oxygen and Nitrogen to ZnO:Al Thin-Films II-Effective Dopant Concentration, Mobility and Lifetime

Exact optical analysis of aluminum doped zinc-oxide (ZnO:Al) thin-films have been shown in [1], as function of reactive O-2- and inert N-2-gas additions to the inert Ar process-gas. Here, a theoretical model is introduced, which allows the determination of typical semiconductor parameters, by use of UV/Vis/NIR spectroscopy-a contact-free measurement method. In detail, effective dopant concentrations, n(e), in semiconducting thin-films, as well as mobilities, mu, drift velocities, v(D), lifetimes, tau, and mean free paths, iota, of electrons within these layers can be calculated. Sputtered aluminum-doped zinc-oxide (ZnO:Al) thin-films have been analysed with respect to reactive oxygen additions to the inert argon process-gas and with respect to substrate-temperatures. The effects of these two parameters on the above mentioned physical values have been investigated and discussed.